“…However, the importance of HU for replication initiation has only been clearly demonstrated for E. coli ( Krause et al, 1997 ; Chodavarapu et al, 2008 ). Several studies have shown HU independent origin unwinding even in gram-negative bacteria ( Donczew et al, 2012 ; Makowski et al, 2016 ; Jaworski et al, 2018 ; Plachetka et al, 2019 ), suggesting that HU-dependence of origin unwinding may be limited to a narrow phylogenetic group. C. difficile encodes a homolog of HU, HupA ( Oliveira Paiva et al, 2019 ) but whether this protein plays a role in DNA replication initiation remains to be established.…”